1. Field of the Invention
The present invention relates to replaceable cleaning pads which deliver a bleaching agent as well as a detersive composition to a surface being cleaned. More particularly, it relates to replaceable cleaning pads that are configured to avoid incompatible chemicals contacting each other prior to use.
2. Description of the Related Art
A variety of cleaning devices are known in which a handle links to a cleaning head. For example, floor mops typically have a handle linked to a sponge-like or rag-like cleaning head. However, such cleaning heads become dirty and/or malodorous over time, and often release undesirable liquid after use. Thus, consumers dislike storing them between uses.
There have been developed replaceable cleaning heads that are used with such handles, so as to create scrubbing devices with low cost replaceable cleaning heads. See e.g. U.S. patent application publication 2004/0117935. See also U.S. patent application publication 2006/0048319, the disclosure of which is hereby incorporated by reference as if fully set forth herein. These devices have the benefit of being able to throw away the cleaning head after each use, and being able to assemble a fresh cleaning head to the handle prior to the next use.
In some such devices the cleaning head/pad merely acts as a scrubbing facilitator, with the cleaning solution being separately applied. In other devices a portion of the pad is impregnated at the factory with a cleaning solution and enclosed in a pouch until use so that the pad remains wet until use. Such devices require relatively expensive packaging as compared to a simple sponge or simple scrubbing pad.
Moreover, using a wet impregnation system restricts which chemicals can be used for the impregnation. For example, a number of surfactants, cleaning adjuvants, dyes and fragrances cannot be stored long term in a liquid medium containing a bleaching agent without inducing significant decomposition of the bleaching agent. Another consideration, especially relevant for halogen-based bleaching agents, is the antagonistic degradation of the bleaching agent via interaction with the pad materials of construction. Also, with a wet impregnation system it is difficult to control migration of various chemical components along the pad without interfering with the ability of the pad to give up those chemicals when used.
Various patent citations teach solid mixtures composed of both detersive cleaning agents and bleaching agents, as part of a cleaning pad/implement, for example U.S. Pat. Nos. 4,935,158; 5,108,642; and references therein. However, combining detersive ingredients with solid bleaching agents can cause the premature degradation of the bleaching agent due to chemical contamination of the bleaching compound, and often restricts the types of detersive ingredients which can be employed in the intimate mixture due to chemical incompatibility. Thus, a cleaning pad which physically separates the detersive ingredients from the bleaching agent would facilitate optimal long-term bleach stability in the manufactured pad provides the formulator with the best array of available cleaning ingredients as well as providing the end-user with a cleaning product which contains essentially non-degraded cleaning ingredients.
U.S. Pat. No. 5,202,045 discloses a detergent laminate for laundering clothes in which the laminate is formed from a single flexible substrate folded into an S-shaped construction. Within one region of the folded substrate is positioned a detergent composition that includes a surfactant in the form of a paste having adhesive strength sufficient to bind the two surrounding substrate areas together. In a second region of the folded substrate separate from that occupied by the detergent composition, there is a second composition, adhesive in nature, containing a component such as a bleach, bleach precursor, enzyme and/or fabric softener. No other bonding is present between the three substrate area flaps constituting the S-shaped construction because the single flexible substrate is intended to open up in laundry wash water to release the detergent composition and the second composition.
U.S. patent application publication 2005/0107282 described a wipe in which surfactant and bleach were applied to the wipe in separate extruded stripes. However, the cost of production of this product could be significant.
More generally, U.S. patent application publication 2002/0132747 disclosed the desirability of using ethoxylated alcohols and alkyl sodium sulfates as surfactants on a wipe, U.S. patent application publication 2004/0102350 disclosed that it was known to add sodium polyacrylate to cleaning compositions containing a surfactant, and U.S. Pat. No. 6,727,215 disclosed a variety of bleaches in a pouch-based system.
Notwithstanding this variety of cleaning devices and cleaning materials, a need still exists for improved replaceable cleaning pads which deliver both bleach and surfactant.